Blood samples: Sampling would be done along with routine sampling as far as possible to avoid additional pricks to the child. Plasma would be immediately separated and stored and tested for Vitamin B12 ,homocysteine, methylmalonic acid and folate levels. This blood would be taken from sample already taken for other tests to be done in the child. Confidentiality of records would be maintained. The study is purely observational and will not influence the management of the child. Though as a standard policy all children with ITS would receive Vitamin B12, folate and other supplements and diet counseling will be done.